The conventional type of a micro stepping motor such as shown in FIG. 1 comprises a rotor 1, a magnetic core 2 having a coil winding L, a stator constructed of two stator pieces 3A and 3B which are fixed to the magnetic core 2 and are opposed with respect to each other around the rotor. A pair of eccentric pins 4A and 4B are respectively positioned in long holes provided in the stator pieces 3A and 3B and it is necessary to accurately adjust the position of the stator pieces 3A and 3B by means of the eccentric pins 4A and 4B for driving the motor in the best condition.
It is difficult to mass-produce and finish the circular portions 3a and 3b of the stator pieces 3A and 3B with a high degree of accuracy. Moreover, the stationary position of the rotor is decided by the fixing in place of the stator pieces 3A and 3B after variably adjusting them to obtain the best motor operating condition.